Pace of play isn't (or at least shouldn't be) about how long it takes to finish a round. That is an effect of pace of play. Pace of play is about being ready to hit when it's your turn, knowing your relief options so you can proceed without delay, hitting a provisional ball if your first may be lost so as to prevent having to return to the tee, perhaps not taking the full five minutes to which the rules otherwise entitle you to search for a lost ball, yielding to faster...

1) I can't believe it took a page-and-a-half for someone to bring up Caddyshack. "The man's a menace!"
2) While I don't take music with me out on the course, and I always put my phone into "silent" mode, if someone in my group or another wants to listen to music while they play, it doesn't bother me. When I have been with someone playing music, I've even enjoyed it, provided a) it's not overly loud, b) it's decent music, and c) the tempo has to be down. No speed...

Ninjas are outside agencies (see definition). According to rule 27-1(c), exception 2, "if it is known or virtually certain that the original ball... has been moved by an outside agency... he may proceed under the applicable rule." In this case, that would be rule 18-1, which calls for the ball to be replaced without penalty. As the ball would no doubt be unfit for play, the player could replace the ball under rule 5-3.
On a related note, would a zombie be...